227 Piece Thread Cutting & Washer Lock Nut Assortment

227 thread-cutting and washer lock nuts in a pre-packaged assortment covering the most common sizes used in domestic vehicle trim, interior panel, and underhood attachment. Thread-cutting nuts tap their own threads as they're driven in, eliminating the need for a pre-threaded hole in plastic or thin sheet metal — a practical choice for plastic trim brackets, air duct clips, and cover panels. What's Included Thread-cutting nuts — multiple sizes for self-threading into plastic or thin sheet metal Washer lock nuts — integrated washer and locking function for vibration-prone applications Multiple sizes covering common domestic vehicle fastener applications 227 pieces total Specifications Fastener types Thread-cutting nuts, washer lock nuts Material Steel, zinc treated Application Domestic vehicle trim, interior panels, underhood covers Total pieces 227 Supplier Auveco Best For Auto body and trim shops — thread-cutting nuts are used throughout vehicle interiors and underhood areas; a mixed assortment keeps common sizes available without managing individual part numbers Fleet maintenance operations — shops that routinely remove and reinstall trim panels, covers, and brackets need both thread-cutting and washer lock nuts in hand for reassembly Restoration shops — original thread-cutting nuts often strip or break during teardown; this assortment covers the sizes typically needed to reinstall plastic and sheet metal components Understanding Thread-Cutting Nuts Thread-cutting nuts (also called thread-forming or self-threading nuts) are designed to cut or form their own mating threads as they're installed. Unlike standard machine nuts that require a pre-tapped hole, thread-cutting nuts create their own thread engagement — making them the right choice for plastic housings, soft sheet metal, and underbody panels where pre-threading isn't practical. Washer lock nuts pair an integral flanged washer with a locking feature (serrations or a distorted thread) that resists loosening under vibration — commonly used in areas of the vehicle exposed to road noise and engine vibration. When selecting a thread-cutting nut, the pilot hole diameter is critical: too small and the nut won't advance; too large and thread engagement will be insufficient to hold. The screw diameter and material being threaded into determine the correct pilot hole size. Questions? Contact us. Shipping & Ordering Ships within 1–2 business days from our warehouse Volume pricing available — save up to 20% when ordering 3 or more Reorder regularly? Ask us about a B2B account with a quarterly restock cadence and custom pricing — contact us